Distant type indicating instrument and the like



Feb. 23, 1932. l T. cAR`RoLL E1' AL 1,846,792'

DISTANT TYPE INDICATING INSTRUMENT AND THE LIKE Filed Jan. 29. 1927wanted Feb. 23, 1932 V.

THOMAS CARROLL AND GEORGE L. DAWSON, orV HAMIroN, vmGiNrA :oIsTAN'r TYPE`1NnIcA'JJIlmy INSTRUMENT ANDTHELIKEV g Application nee Jamiary 29,1927. se'riaiNo. 164,497.

This invention relates yto certain improve- Y ments in distant typeindicating instruments and the like; and the natureand objects of theinvention willbe readily recognized and understood by those skilled -inthe arts in'-.;

volved in thelight of the following explanationrand detailed descriptionof the accompanying drawings, illustrating whatwe, at present, considerto be the preferred embodiments or mechanical expressions of ourinvention from lamong various otherforms, ar-v rangements, combinationsand constructions of which the invention is capable within the spiritand scope thereof.

More particularly the invention .is directed to the solution of certainproblemsV and themv elimination of certain disadvantages encountered inthe operation and use of indicatingl instruments and the like ofthe'distanttype, that is, of the type in which the indicating instrumentislocated at a distance from the`v location of the conditions kto beindicated, such for examplejas instruments ofthe pres-l sure operatedtype exemplified by thermometers ofthe Bourdon' gage type forindicating` temperatures. This type of thermometer Or temperatureindicating instrument is of gen-v eral use and application on and 1nconnection with automotive vehicles such as automobiles, aircraft, andboats,for indicating the temperature ofg-the cooling liquid of aninternal combustion motor driving the same; k'In the use of theseinstruments on aircraft, such as airplanes, `the indicating instrumentor gage is generally/.located on the pilots instrument boa rd, and isoperatively coupled through the medium of a capillary tube with abulblo-V cated atthe point where the temperature is to Y be determined. Thecapillary tube and bulb 40 are filled with a fluid under-the properYpressure and the tube is permanentlyconnectedto and forms a fixed partof the VpressureV or Bourdon type of gage, so that the bulb Vforms thethermal element and the uid therein ex,- pands and contracts in`accordance with temperaturefchanges; to varyl the pressure ofthe fluidin the capillary tube and thereby cause actuation :by the pressure ofvthe "Bourdon gage to give an indication or reading of 'thetelnperatureat the thermal element. 'These capillary tubes arevjeryvfragile and delicate I l as will be readily understood `by thosefamiliar with thesetypesof instruments and great difficultyisencountered through breakage thereof dueto vibration, shock and otherconf. ditions encountered withthese instruments mountedonan airplanerorother vehicle.

When a break occurs in one of these capillary l tubes, or a leak of anykindoccursQtheinstruf. Y ment with which'lthe tube isgconneotedfis 60rendered useless vfor giving accurate readings or indications. ,Underthe prevailingrpractice and construction ofthese typesof instruments,breakageof the tubeor leakage therein, necessitates removal of theentire ,assenti-v bly (gage, tube and .thermal element) andl thereplacement thereof'with a'newgage,V capillary tube and thermal element.AIt is necessary with these instruments,A` that the capillarytubeVK beattached into operative relation with-the' gageI before installation, inorder to maintain the proper Yand required Ypredetermined Vpressureofthe fluid within the tube and thermal element and the gage.

.A fundamental andpriInaryxobject of the Vpresent lnvention, is toeliminate, the fore? going disadvantages of thetypesl of indieating`instruments referred to by the provision of a capillarytube andA thermalvelement which forms a sealedunit for attachment to anindicatinginstrumentof thepressure type,.so that upon breakage ofor leakage in atubeor thermal` element, the same J can bereadily and quickly' removedand a new capillary tube unit inserted in its place 55 1n operativenon-leaking connection and yrelation with the instrument or gage,withoutly removing yor discarding 'and replacing *the* gagej f. v

A further object ofthe invention residesvin '90 the provision of anindicatingv instrument of the pressure orkBourdon type having afre-4movable capillary tube which `formsa. sealed unit when applied to thegage and connected therewith, and which sealed unit is iunsealed* by theact of attachment to theinstrument or gage forvplacingthe capillary tubeand its containedl fluidVv in non-leaking connection with the gage.

f further object of the invention liesin 103 i strument or gage of thepressure actuated ment by a new unit.

type, which fitting is leakproof in attached position, but which isreadily detached to permit removal of a tube unit and replace- Anotherobject ofthe invention is to provide a gage of the pressure or Bourdontype, having a member for puncturmg or unsealing a sealed Capillary tubeunit' whenV such unit' is attached andconnectedin operative rela-k tionto the gage. v

VA further object of the inventionisto provideA a detachable couplingand fitting for securing asealed fluid containing tube unit to and with'an element with whichl said unit is to be placed in communication, thesaid coupling and vfitting' punctnring or unsealing the tube unit whenthe Asameis applied and attached. v Y Y' Another object'of the inventionis'to provide as a new article of manufacture, a sealed capillary tubeand bulb unit,having the contained fluid under the proper predeterminedpressure for use with pressure gages or in dicating linstruments as`-replacements *for broken or leaking tubes and elements of suchinstruments, and to Vfurther `provide afdetachable coupling or fittingfor connecting such a unit to a gagey andfor puncturing 'vor unsealingthe unit when coupled to the gage.

'vrWith the foregoing ygeneral objects 'and certain other objects andresults in'fview, which other objects and results will be read ilyapparentfrom thefollowing;explanation, the invention consistsin certainnovel features in constructionand in combinations and arrangementsofelements, as will beV more fully, and particularly referred to andspeciiiedhereinaften Y Referring to the accompanying drawings inv whichsimilar Vreference', characters refer to. corresponding parts throughoutthe several figures thereof:

kFig.l` is a'view in side elevation, more or less diagrammatical,showinga' thermometer of the Vpressure or Bourdon' gage type mounted onand installedin an finstrument board, a lportion of which only isshow-n,`of an airplane, with the sealedunit of the invention embodyingacapillary tube and thermal element in mountedl and-'applied operativepo-YV sition and relation on'and in connection with thegage. Y A

Fig. 2 -is1 a` Vvertical transverse section through the fitting andcoupling removably connectingand attaching the tube unit tothe t gage,showing thexcouplin'gr in Vposition for application and connection tothegage to unseal the Vtube andV place the same in nonleaking connectionandcommunication therewith.

lFig. 3 isa vertical sectiontaken on 'the line 34-3 of Fig. 2, andshowingthe sealed inner vstruments.

end of the tube unit for puncturing or vun"- sealing bythe gage fittingor nipple.

The invention is disclosed herewith as embodied in a pressurethermometer of the Bourdon type for mounting on and in connection withan airplaneV instrument board and internal motor cooling system. rlhisapplication andv adaptation of the principles and features of theinvention are presented purelybv wayof exampleand not of limita-`tion,andV were selected because','with the inous, to those familiar'with thefart,thatthe Yprinciples* and features of the invention arecapableV offa wide range of adaptations and applications to a variety ofother types of-instruments for other purposes and for mounting aninstallation in other ways and in 'con-y nection with other elements.Hence, it is notk in any wayintended to limit the invention or restrictthe same to the embodiment, application ,and installation, or to thetype of instrunient presented herewith for thepurpose of explaining theinvention to enable those skilledfin the art tofunderstand the same.

` In Fig.I l Vof theiaccompanying drawings, a'portionof an airplaneinstrument board A is shown@ with a thermometer Bv of the BourdonVo'rfpressure gage type mounted thereon and'therein with the indicatingface of Vthe instrument visible on the' instrument Aboard and the bodyof the instrument extending H rearwardly throughthe instrument board, inr the usual manner welll understood by those familiarwith the mounting'of aircraft in- The l"thermometer .or gagev B is operatively coupledyand connected with a capillary tube unit C which extends to and is incommunicationA with a bulb or thermal element T for mounting at and inthat portion or point of the motor cooling system from whichV it isdesired to indicate the temperatures'at the gage B on the instrumentboard A; VAsreferred to hereinbefore, according tov the prevailing andgenerally employed, construction Y'and arrangementA of thesedistanttype'indicating instruments', the capillary tube C is permanentlyfixed and connected to theinstrument or gage sothat it is impossibleorimpracticable to replace 4or renew a broken or leakingtube or thermalelement, with the result that the gage and its K connected capillarytube'a-n'd thermal element must be Yrenewed and completely replaced bytube C provide'a sealed unit removablyfand iao itc

. with the thermal element T =ixed to the tube` detachahlv coupled toand connected with the gage B,.for replacement by anothersuch unit whendesired or Vfound necessary, all without removing and discarding orreplacing the instrument or gage B. In the example of the inventiondisclosed herewith, thetube unit C` embodies the capillary tube enclosedwithin a protecting and guarding tube or casing 11,

, fixed and secured over and closing the end of casingll with the endVofcapillary tube 10 iitting tightly in and extending through the boreof the end block 12. `A sealing cap or closure' 14, is fitted tightlyover and on and around the end block, with theouter or end wall ofthecap or closure 1174, spaced outwardly a distance from the outer'trace of block 12 to form a'chamberrl between the end block and wall 15with which the vcapillary tube 10 is in communication. Theedge of thecap or closure 14, preferably lies flush with and as a continuation ofthe adjacent face of end block 12, as will be clear by reference to Fig.2 or the' drawings. .The endwall 15 of the sealing cap or closure 14, isformed with an annular groove 17, around its outer and the instrument orgage end of the tube 10,`

face adjacent and in proximity to the side wall or flange of the cap,toform a .weakened structure so that, pressure applied to the wall 15 willbreak or rracturefthe samefat ,the groove, andsever this wallL 15 fromthe cap'. It desired or found expedient, the yend .wall 15`oi`thesealing cap 14can be formed ora soft material which can be readilypiercedor punctured orcan be formed, ir desired, ora v' franoible andreadil broken material .all of` 21 Y 7 which willbemore VVrully referredto andiexplainedV hereinafter.` i. The capillary tube unitC, withthebulb or thermal element' T,

sealed and closed "againstleakage by `the co` operating end block 12 andclosure cap 14, is filled or charged with afiuid under a predeterminedrequired pressure for the instrui ment with whichV it is to be employed,so that i changes oi. temperature, when installed, will cause theexpansion and contraction of `the fluid in the thermal unit T withcorrespondingV variations and pressure in and through the capillarytubel 1.

The gage or instrument B is formed with a coupling member or nipple 18which extends rearwardly 'from the gage. andis formed with an inwardlvextending recess or opening to receive and form a tight running lit withthe sealing closure at and on the gage end of the tube unit C. Theexterior sidewall or.`

nipple 18 is screw threaded and the base or inner-end yof. the recess oropening in the nipple, is closed bvwall 19 having a central or axialproj ecting` point or head 20 of relatively cone s'hape,having anointedouter end. A duct or passage 21, is formed through the baisel or innerend wallfor the nipple 18, extending axially therethrough to the coneshaped prov j ecting point'2() where itis in communication withlateralports or openings'22 through theY sidewalls of head 20,7toplacethe chamber 16 in communication with duct or passage 21 throughthese head ports 22. The `duct or passage 21'extends inwardly to thegageor instrument B where it is in operative communication with thepressure actuated elei ment or member or the gage (.notshown) as willlbereadily understood by thosefamiliar with these types of gages. V

'- The tube unit C is adapted to necting or coupling nipple 18 of thegage B,

be coupled Y and connected at its sealed end with the conand this isaccomplished by the provision of an internally screw threaded couplingmem,`

ber 23 adapted to be threaded overland screwed. on .to the externallyYthreaded gage nipple 18.V The coupling member 23 is'pro vided with theouter end wall 24 having thev central opening l25V therethrough whichloose.

` ly receives and through which fthe tube unitl C extends, withthe-innerface or" thewall 24 rotatably bearing upon the outer faces ofthe end .block 12, andthe side wall .of thesealing cap 14,V which'willbereadily understood by reference to Fig. 2ofthe accom'- panying drawings.The sealedtube unitinf cludes and has the couplingmember 23V loose-z lymounted thereon for coupling the unit to a gage as will be explainedhereinafter.

`inthe operation anduse of the gageand tube unit of the invention, thegage A' is mounted: at the desiredipoint, such for example as on theinstrumentboard A, and a tube Vunit C of the. properlength `iforthe i1istallationwith lwhich it is to'be.used,-is mounted with the .thermalunit-',or'bulb-.T thereof, disposed and located at the point at whichtemperatures are to be taken.' The sealed end oi. the tube unit havingthe capV 14, and the coupling member 23, is then in-.

serted in and over the gage or instrument connecting nipple 1.8, withthe sealing'capvl4, 1

iittingislidably and tightly within theVv open-l ing or recess Vof thenipple and the coupiing member iitting over'the nipple yfor threaded.l

engagement therewith. Then, by screwing the couplingrmember v23 over andinwardly 5 wall 19 thereof until the end wall 15 oi cap 14 is 'engagedbythe projecting point'or head 20. Upon Vcontinued inward movement ofthe sealing cap 14 by the coupling member 28, the end walllof the capwill be broken or fractured along the groove 17 from the cap, and thechamberl will then be placed in communication through ports 22 Awith theduct or passage 21 leading to thegage operating mechanism. The end walllafter it is broken from the cap is then loosely confined between theblock 12 andhead 20, it being obvious that the couplingmember 23 is notscrewed onto nipple 19 a sufficient distance to force wall over andclosing the tube end'. Any suitable arrangement being provided to Vlimitinward movement of the coupling member, as for example, by terminati ingthe exterior'threads on the nipple at the proper distance inwardly fromthe outer end of the nipple. Upon breaking or fracturing cap wall 15,the fluid under pressure within the previously sealed tube unit C,passes into the gage through vpassage 21, and the pressure in theinstrument and unit C with thermal element T is the same or equalized,so:

and increasingthepressure of the fluid with-A in thecapillary tube 10,and the gage actuating mechanism to cause operation thereof Y andindication by the gage of the temperature at the thermal element T.Attention is vhere directed to the fact that the inventionA is notlimited to the form'of breakable or fracturable sealing cap shown inwhich ythe end wall 15 of the cap is' severed or broken from thecapbythe projecting head 20, but that the invention contemplates andincludes a. soft material capend wallfor piercing or puncturing by theprojectinghead 20, or of a frangible material which canbe broken byengagement with the'head. Y g

lvith an instrument and capillary tube unit of thefinvention installedand in operation and use, in the eventof breakage or leakage at anypoint in thecapillary tube or element T, the tube unit can bequicklyremoved Vby unscrewinff lease the heated endof the unit from the gagenipple, and the unit may then be removed from the installation. A new orreplacement tube unit can then be quickly installed,the

fluid in the unit being sealed therein under the proper pressure, byapplying the coupling member to the gage nipple and forcing the sealedend of the new tube unit into-the nipple where it is broken and unsealedby .engagement with head 2() andthe capillary tube with its fluid underpressure, placed intween the tube unit and the gage, yet, whichl thecoupling member 23 'to re- Y connection can be readily uncoupled anddetached and coupled and appliedvasV may be desired. It is essential totheproper successful operation Ofthese types of pressure indicatinginstruments, that there'be no leakage of the fluid under pressure whichoperates the same, otherwise accuracy and proper operation isimpossible.y The detachable coupling provided by the'invention for andbetweenl a sealed tube unit having a. fluid under pressure therein,and agage or other element placed in communication with such unit, insures alealrproof connection and coupling with resulting accurate operation ofthe instrument. v

`'While the invention is primarily intended for use andembodiment withindicating instruments of the pressure type, and is so shown anddescribed, herewith, `it is also applicable and adapted for use broadlyin providing a coupling between a sealed unit with fluid under pressuretherein, and an element to be v,placed in communication with such unit.Further, the arrangement and construction lof `the sealed end ofthe tubeunitk having a breakable, puncturable or shatterable cap end wall, iscapable of general use for variety of purposes, and particularly incombination with the arrangement of coupling/member and attaching.nipple withV itscap engaging and breaking projecting head. Attention ishere directed to the fact that the broad principles of the inventioncontempla-te and include `other means and constructions for closing thetube unit, such `for example by a low fusing point sealing materialwhich when melted by application of heat opens the tube; orrbydistortion of aportion ofv the unit to close the tube, such that forceapplied to the tube in the required Vmanner and direction will open thesame;

the invention broadly residing in the provision-of a presealed capillarytube unit. and the like for attachment to a means or instrumentalitywith which it is-to be utilized.

It' is also `evidentthat various changes, modifications, variations andsubstitutions might be resorted to without departing from the spirit andscope of our invention, and hence we do not wish to limit "ourselves tothe exact and specific disclosures hereof.

Desiring to protect our invention in the broadest manner legallypossible, what we claim and desire to secure by Letters Patent oftherUnited States, is:

1. As a` new article of manufacture, a sealed capillary tube unit,embodying a capillary tube and a protecting casing therefor, one end ofthe casing closed by an end block through which the. capillary tubeextends, and a sealing cap over saidend block. i

' 2. As a new article of manufacture, a sealed capillary tube unit,embodying aicapillary tube and a Vprotecting casing therefor, Aan endblock closing the casing, the capillary fige-rejas V having its end wallspaced therefrom to' form a chamber in connnunication with the tube,

Vand the end wall of said sealing cap beingV constructed to be rupturedto open-said chamber and tube.

3. As a new article of manufacture, a sealed capillary tube unit,embodying a capillary tube and a protecting casing therefor, an endblock closing one end of the casing, the capillary tube extendingthrough said block, a sealing cap Xed over the end block with the capend wall formed with a weakening groove to permit said wall being brokenfrom the ca 4. Ig combination, an instrument of the pressure actuatedtype, and a presealed capillary tube unit, connected to said instrument,f

the said instrument having means for unsealing said unit-when attachedthereto, to.place the tube unit in communication with the 1nstrument. i

5. In combination, an indicating instrument of the pressure type, and apresealed capillary tube `unit for attachment and-connection to saidinstrument, a connecting nipple on the instrument,the said `nippleproviding means for unsealingV said unit in attaching the same thereto.g Y 6. In combination, an indicating instrument of the pressure type, apresealed capillary tube unit for attachment to said instrument, theinstrument end of said unit formed with a breakable sealing member, andthe said instrument provided Awith means for breaking saidsealingmember, when the un1t is attached to the instrument.

7 In combination, an indicating instrument of the pressure type, andapresealed capillary tube unit for attachment to said instrument, theinstrumentprovided with an attaching nipple for receiving an end of thetube unit, the instrument end of the tube unit provided with a breakablesealing cap, and the said nipple formed with a projecting head forengagement with the tube sealing cap to break the same and placev thetube unit in communication with the'instrument. Y

8. In combination, an indicating instrument of the pressure type, and a`presealed capillary tube -unit for attachment to said instrument, thetube'unit provided latone end with a breakable sealing cap, a"connecting nipple on the instrument, having a recess for tightly andslidably receiving the sealing cap end of the unit, a coupling membercarried by the tube unit for securing the same to the connecting nipple,and a member on the nipple within said recess for engaging andrupturingthe sealing cap to open the tube unit for communication with theinstrument.

9. An indicating instrument of the pressure type, having a connectingnipple forV attachment to a capillary tube unit, Vthe nipple with ia'central' outwardly openingV recess, a projecting head member attheinne'r place thetubein communication Withthein- Y S10.` As anewfarticle of manufacturm a sealedcapillary tube unit* for attachmentto aninstrument vof thepres'sure type, embody- Y ing acapil'lary tubeanda protecting casing therefor, vmeans for closing thecasingat theinstrument end thereof around the tube, and

- a sealing member closing that end of the tubei at the closed end ofthe casing.

ll. In combination, an instrument of the .pressure type, a presealedcapillarytube unit sinv for attachment to said instrument, the instru'-ment end of saidunit sealed, and said instrument providing means forunsealing such end of the tube when the unitis attached to theinstrument.

l2. In'combination, an instrument of the pressure type, a presealedcapillary tube unit for removable attachment to the instrument, andsaidtube yunit provided with a seal to-be opened on attachment of theunit in operative relation withthe instrument.

13. As. a new article of manufacture, a pre- -sea-ledcapillary tube unitVfor attachment to aninstrument, the instrument end of the tube providedwith a seal closing the same, and said seal adapted to be opened whenthe unit Y is attached to the instrument.

Y 14. 'As new article of -manufacture, a .l

sealedcapillary tube unit for attachment to an instrument, said unitembodying, a capila seal closing the instrument end of the tube.

l5. rasa new'article of manufacture, a cap- .lary tube, a vprotectingcasing therefor, and

embodying a sealed capillary tube charged i with a iiuidunder pressure,said tube having Y *Y a seal atrone end constructed to be unsealed y yandopened upon attachment to an instrument.

16. As a new article ofmanufacture, a sealed capillary tubev unit foroperative attachment to an indicating instrument of the pressure type,said unitincluding a sealed capillary tube having a fracturable sealingmember at and sealing that end' ofthe tube to be operatively connectedto the instrument, and said sealing member adapted to be fracturedtounseal the tube for attachment of the unit in operative relation withthe instruyment;vv l 17. AsA a new ,article ofmanufacture,V a

sealed capillary tube-unit for Operative at- 5 .tachment to anindicating instrument of the q Y Y pressure ty e, saidunit including asealed lcapillary'tu e, a sealingcap having atractu'rable end Wall atand sealing that end VO v the tube to be operatively connected with the'y 10 instrument, Said cap end Wall adaptedto be racturedto unseal theVtube for attachment of the unit and the tube thereof in operativeyrelation with the instrument,V and means for attaching the unit andoperatively connecting Y i5 the tube to the :'Lnstrument.v Y v e fSigned at Hampton, vElizabeth City County, Virginia, thislOth dayOf-.January,Vv

1927.. v e a Y THOMAS CARROLL. am Y GEOL. DAWSON.

